Urethra
|
Bull
-
It is a long mucous tube extending from the neck of the bladder to the tip of glans penis
-
It passes backwards on the floor of the pelvis, turns around the ischial arch forming a sharp bend and then passes forward to be included in the body of the penis
-
It has therefore pelvic and extra pelvic or penile parts
-
The pelvic part is 12 cm long and is relatively small and uniform in diameter
-
The urethral muscle encloses it ventrally and laterally and is very thick
-
It is related to the rectum and prostate above, the obturator muscles below and the Cowper’s gland laterally
-
The extra pelvic or penile part passes between the two crura of the penis turns forward and is included in the body of the penis
-
Here the corpus spongiosum and bulbo-cavernous muscle covers it. The tube forms an enlargement at its beginning, the bulbus urethrae
-
It then gradually diminishes in diameter and very small at its termination, forming processus urethrae
-
The opening from the bladder into the urethra is termed internal urethral orifice, it is closed except during urination
-
The terminal opening is known as external urethral orifice.
-
The colliculus seminalis is a rounded prominence, situated medially on the dorsal wall about 5 cm behind the internal urethral orifice and on it are two slit-like openings situated close together
-
-
The urethral crest is a median ridge of mucous membrane in the dorsal wall of the urethra
-
The crest extends forward from the colliculus, while two mucous folds pass backward from the colliculus
-
A little lateral and caudal to the colliculus are the openings of the prostate and behind are the ducts of the Cowper’s gland
Species difference
Ram and Buck
-
The urethra lies in a groove on the ventral surface of the corpus cavernosum.
-
Its terminal part projects commonly about an inch and half beyond the glans penis, forming twisted processus urethrae.
Stallion
-
Pelvic part is 10 to 12 cm long and 5 to 6 cm in diameter.
-
The extra pelvic part is 1.5 cm in diameter.
-
-
Lateral to this are the openings of the prostatic ducts and further back are openings of the ducts of the Cowper’s gland
Boar
Dog
-
The bulb of the urethra is well developed
Rabbit
Cock
|
Last modified: Friday, 16 July 2010, 10:37 AM